Flask 管理员显示枚举值而不是名称

Question

我有一个模型，它使用枚举来定义访问级别，如下所示：

class DevelModelView(ModelView):
    edit_modal = True

    def is_accessible(self):
        return current_user.is_authenticated and current_user.access is AccessLevel.DEVEL

class DevelStaffModelView(DevelModelView):
    column_editable_list = ['access']
    column_filters = ['access']
    column_searchable_list = ['login', 'email']
    form_choices = {'access': [(AccessLevel.DEVEL.name, AccessLevel.DEVEL.value),
                               (AccessLevel.ADMIN.name, AccessLevel.ADMIN.value),
                               (AccessLevel.STAFF.name, AccessLevel.STAFF.value)]}

枚举定义如下...

class AccessLevel(Enum):
    DEVEL = 'Developer'
    ADMIN = 'Administrator'
    STAFF = 'Staff Member'

使用 form_choices 属性，我能够以值形式（IE：开发人员）在模态和可编辑列选项中显示，但不幸的是，显示仍在使用名称（IE：名称）。

为了澄清，我实质上是在询问是否有任何方式让 Flask Admin 在显示表中显示枚举的值，而不是默认的名称。提前谢谢你...

还提供 Staff 模型以防万一……

class Staff(db.Model, UserMixin):
    id = db.Column(db.Integer, primary_key=True, autoincrement=True)
    login = db.Column(db.String(64), unique=True)
    _password = db.Column(db.String(128))
    email = db.Column(db.String(100))
    access = db.Column('access', db.Enum(AccessLevel))

    @hybrid_property
    def password(self):
        return self._password

    @password.setter
    def password(self, plaintext):
        self._password = bcrypt.generate_password_hash(plaintext)

    def check_password(self, plaintext):
        return bcrypt.check_password_hash(self._password, plaintext)

    def __str__(self):
        return "%s: %s (%s)" % (self.access.name, self.login, self.email)

Answer 1

如果您要显示多个 enum 类型，而不是创建单独的 column_formatters，您可以更新 Flask-Admin 使用的 column_type_formatters。

示例

from flask_admin.model import typefmt


class AccessLevel(Enum):
    DEVEL = 'Developer'
    ADMIN = 'Administrator'
    STAFF = 'Staff Member'

# ...

MY_DEFAULT_FORMATTERS = dict(typefmt.BASE_FORMATTERS)

MY_DEFAULT_FORMATTERS.update({
   AccessLevel: lambda view, access_level_enum: access_level_enum.value  # could use a function here
})


class DevelModelView(ModelView):

    column_type_formatters = MY_DEFAULT_FORMATTERS

    #  ...

还可以考虑按照SO answer 中的说明设置 AccessLevel 选项。这意味着您不必在模型视图定义中重复枚举名称/值。注意AccessLevel 类中的__str__ 和__html__ 方法。

示例

from flask_admin.model import typefmt
from wtforms import SelectField


class AccessLevel(Enum):
    DEVEL = 'Developer'
    ADMIN = 'Administrator'
    STAFF = 'Staff Member'

    def __str__(self):
        return self.name  # value string

    def __html__(self):
        return self.value  # option labels


def enum_field_options(enum):
    """Produce WTForm Field instance configuration options for an Enum

    Returns a dictionary with 'choices' and 'coerce' keys, use this as
    **enum_fields_options(EnumClass) when constructing a field:

    enum_selection = SelectField("Enum Selection", **enum_field_options(EnumClass))

    Labels are produced from enum_instance.__html__() or
    str(eum_instance), value strings with str(enum_instance).

    """
    assert not {'__str__', '__html__'}.isdisjoint(vars(enum)), (
        "The {!r} enum class does not implement a __str__ or __html__ method")

    def coerce(name):
        if isinstance(name, enum):
            # already coerced to instance of this enum
            return name
        try:
            return enum[name]
        except KeyError:
            raise ValueError(name)

    return dict(choices=[(v, v) for v in enum], coerce=coerce)


class DevelModelView(ModelView):

    column_type_formatters = MY_DEFAULT_FORMATTERS

    #  ...

    form_overrides = {
        'access': SelectField,
    }

    form_args = {
        'access': enum_field_options(AccessLevel),
    }

    # ...

Answer 2

您需要column_formatters 功能才能在表格中显示正确的值。格式化函数定义如下：

def access_level_formatter(view, context, model, name):
    db_value = getattr(model, name)
    enum_value = getattr(AccessLevel, db_value)
    return enum_value.value

您需要在视图类中指定此格式化程序，它用于access 列：

class DevelStaffModelView(DevelModelView):
    column_formatters = {
        'access': access_level_formatter,
    }